Figure 4.

Flashing a light during inter-trial intervals retarded learning most when done contingent upon hippocampal SPW-Rs. During the first 8 training sessions, animals in the yoked control (Y) and SPW-R-contingent (R) groups received a light stimulus during the inter-trial interval every time a SPW-R was detected in an animal belonging to the R group (Disruption), whereas the animals in the normal control group (N) did not receive any light stimuli. After that, animals in the yoked control and SPW-R-contingent groups were trained for another 5 days, this time omitting the light (No disruption). Vertical lines depict s.e.m. Asterisks refer to repeated-measures ANOVA group effects: ^*p < 0.05, ^***p < 0.001.